A tiller or steering arm has been frequently used to control the direction of a steerable marine drive having a pendant drive unit which is selectively rotatable about a substantially vertical axis. Such drive unit generally provides a selectively driven propeller to provide a steering thrust to the boat. In addition, some constructions have employed a pivotal vane having a surface within the slip stream of the propeller to apply torque upon the vane surface and provide a turning movement to the inter-connected drive unit.
One or more cables have generally been used to connect a steering control or helm to the drive unit to control the rotation of the pivotal vane and/or the steering arm. Such cables may have cores or internal rods which move either axially or circumferentially to control the pivotal position of the vane and/or steering arm. It is also possible to employ hydraulic control fluid to control the rotation of the vane and/or steering arm.
Some systems have attached a rotatable link directly to the steering arm to provide an inter-connection between a steering control and the rotatable vane. Such linkage is rotated to initially control the rotation of the vane within predetermined limits and thereafter directly controls the rotation of the steering arm, such as in the Conover U.S. Pat. No. 2,993,464; the Broadwell U.S. Pat. No. 3,149,605; and the U.S. application Ser. No. 06/106,833 entitled "Vane Steering System For Marine Drives" filed on Dec. 26, 1979 by Edward John Morgan and Neil Allan Rohan, and assigned to a common assignee herewith.
One system provides a connector employing an axially movable rod connected to a rotatable vane and moves within a tubular socket so that a slidable pin selectively engages the ends of a longitudinal slot to directly rotate the drive unit, as in the Kirkwood U.S. Pat. No. 3,943,878.
Another system utilizes a spring loaded guide tube to couple a control cable to both a steering arm and a pivotal vane, as in the U.S. application Ser. No. 06/139,001 entitled "Marine Drive Vane Steering System" filed on Apr. 10, 1981 by Russell F. Ginnow, and assigned to a common assignee herewith.